When connected to a mains of 250V; the fuse rating in the plug of an electric device of 1 KW is?

A. 2 A
B. 3 A
C. 4 A
D. 5 A

Correct Answer:

Option C = 4 A

Explanation

1 KW = 1000 watts, power P = IV, thus for a mains of 250 V, the maximum permissible Current I = 1/V = 1000/250 = 4 A
Thus the fuse rating in the plug should be 4 A